ABUJA, June 19 (Reuters) - Nigeria’s President Muhammadu Buhari will sign the 2018 budget into law on Wednesday, a presidency spokesman said.

Femi Adesina, in an emailed statement issued on Tuesday, said the spending plan passed by parliament last month would be signed on Wednesday at 12 p.m. (1100 GMT).

Africa’s top oil producer emerged from its first recession in 25 years in 2017, helped by higher crude prices, but growth remains fragile. The recession was largely caused by low crude prices and militant attacks on energy facilities, since oil sales make up two-thirds of government revenue.

Parliament passed a 9.12 trillion naira (29.8 billion) spending plan last month which is higher than the 8.6 trillion naira budget presented to parliament by Buhari in November, because lawmakers increased the assumed oil price to $51 per barrel, from $45.

The spending plan must be signed by the president to be passed into law, but it was not immediately clear whether Buhari would sign off on the budget in its expanded form. ($1 = 314.5000 naira) (Reporting by Felix Onuah; Writing by Alexis Akwagyiram; Editing by Catherine Evans, William Maclean)